Charles l



(No Model.) 5 Sheets-Sheet 1.

O. L. P. MULLER, Decd.

G. B. CARSTENS, Administrator. REGULATOR FOR DYNAMO ELECTRIC MAGHINES.

L zmzmmfw *wmmimW iiiiifiiiif mmeys (No Model.) s Sheets-Sheet 2.

C. L. P. MULLER, Deod.

, C. B. CARSTENS, Administrator. REGULATOR FOR DYN JELEOTRIG "MAQHINES.

Patented A r;17,1894.

R G. B. CARSTENS, minis ra or ULATOR FOR DYNAMO 5 Sheets-Sheet 3. Deod.

t t ELECTRIC MACHINES. I Pate he I pr. 17, l I l I I 1 l I l 1 I 1' -,1I""T F 1 i I 0. L. P. MU

(No Model.)

REG No. 518,349.

- (No Model.)

v Sheets-Sheet 4. C. L. P. MULLER, Decdq p G. B. CARSTENS,- Administrator. REGULATOR FOR DYNAMO ELECTRIC MAUHINES.

No. 518,349. Patented Apr.- 17, 1894.

(No Model.) 5 Sheets-Sheet 5.. O. L'. F. MULLER, Decd.

C. B. CARSTENS, Administrator REGULATOR FOR DYNAMO ELECTRIC MAGHINES.

349. Patented Apr. 17, 1 894.

Wh fia a sea UNITED PATENT OFFICE.

j oHA-n-Lss L. F; MULLERLQF MILWAUKEE, WISCO NSlN;-' oriAaLEs-n. oARsrnns, E SAME CE. ADM NISTRAT Fgsnm MiiLLEa; h c-EAsEo, as; sienna, o 'THE WISCONSIN Emsoraio; LIGHT sup Powa. company,

or WISCONSIN.

REGULATOR FoR DYNAMIC-ELECTRIC MACHINES...

srncir'roa'rroiv forming partpf Letters Patent No. 518,349, dated Apri 117 1894r 4 .ipplloatlcnfilcdlllay13.1889. siennmslonsr; (No modelJ- description of the'invention, which'will enable others skilled, in the art to which it pertains to to makeand use the same, reference being had to the acqompanyingdrawings, and to the lettors of reference marked thereon, which form apart of this specificatio i i The main objects of my invention are first to regulate thestrength of the. working current byexoluding from activity the coils of the armature supplying the exciting current] certain peculiarities-of. construction and arfor a greater or less portion of their angular movement and thereby decreasingor increaseo ing the inductive action of the field magnet upon, the armature supplying the working current; second, to produce working currents.

of difierent degrees of quantity or intensity :by variously coupling the coils or conductors of arevolvingarmature, and-third, to efi'ect a gradual change in quantity or intensity of the working current. I

' It consists essentially of a rotary armature provided with independent coils or pairs of c .diametrically opposite con nected'cojls; a com-' mutator having divided circularringsor semicircular. plates arranged in pairs corresponding in number and angular position with the number and angular position of said coils,

5. with the free ends of which the semicircular platesar'e connected in corresponding pairs; at like 'number ofbrushes connected in series or single circuit working withthe semicircular plates of said commutator the. brushes of 40 one or both sets being capable of angular movement toward and from each other about the periphery of,said commutator; automati-. cally controlled regulating mechanism'connected with and arranged to impart said-an- 5 gular movement to one or both sets of brushes or their holders, and of certain other peculiarities in the construition and arrangement offthe'current regulating apparatus or' mechanism hereinafter specifically set forth.

It. consists further of one or morejrevoluble 5o armatures provided with independent simple or compound coils or pairs of connected. coils, a commutator having a likenumber of pairs ofsemicircular or segmental plates connected with the free ends of; said coils, and corre sponding in their angular position with reference to the axis of rotationto the angular position of said coils' a'like number of pairs of brushes working with the several pairs of commutator sections a device by-whichthe several pairs of coils or their terminals may be variously grouped or combined in series, or in multiple arc orparallel or in groups of two,

"three, four, &c..to producecurrents of difier-- ent degrees of quantity audIintensity and'of rangement' hereinafter specifically set forth. lt consists further in dividing the several .armature coils into sections and of providing a device whereby the sections of each coilfor '76 of each pair of coils/may be combined in series multiple arcs; or groups for producing. currents.of different degrees of quantity or intensity.

" It consistsfurther of a'commutatorcomposed of pairs of segmental sections each connected with the free ends of a corresponding number and arrangement of independent armature conduct'ors of coils combined 'inseries, 1 a corresponding number of pairs bf brushes working with the several pairs of commutator sections, oneor both sets of brushes or one or both-brushes ,of each pair being movable circum ferentially toward and away fromthe other, whereby a greater or less length of said 8 5 armature conductors or number of windings are engaged at anyone timein the production of the working current, of a governor by which the desired strength or current is maintainedwhen its intensity is changed by moving said brushes, and of certain peculiarities of construction and arrangement hereinafter specified and pointed out in the claims.

- Inthe. accompanying drawings like letters designate the same or similar parts in the several figures. v Figure l is a developed plan ordiagram of a machine embodying my improvements} Fig.

2 is a medial, lougitudinalsectiou'of the same. Fig. 3 is across section through the field magi net and armature, showing one of the a'rma-' tnre sections in side'eleva'tion. Fig, 4; is a dcveloped planrvi-ew cl? theswitch for variously coupling the armature coils in series, multiple are, or groups. Figs. 5, 6, and 7, are detail views of the device employed to eonpiesec tions of thearmature coiis in multiple arc,

groupsor series. {Fig.t8 isa cross section of the commutator or the working'circuit. Fig. 9 is alike sectionof the switch or grouping device taken onthe line a; at, Kiga i, and representing that part ofrthe device to the left of said line! Fig; lO'is-an eudQ-elevationpf the regulator or mechanism for automatically changing the, positions oflth'e brushes in the exciting eirTcuit. Fig-.11 is a reverse View of a portion of saidmechanismyand Figs lzlto 17 inoluslve are diagrams illustrating the operation and efiect of changing the; relative.

positions of. the brushes;

For convenience in illustrating. my im provements, I havel'shown the'arni'ature enh ployed for exciting the lieldmagnet'and the armature-supplyingthe work-ing current with their commutators all mounted upon the same shaft or axis, althoughflimay withjthesame results employ anen' tirel'y distinct and-independent exciting-mechanism} g -'-Referring'to Figs; 1,.25and3 represents the armature which fui'ni'shcs'ihe current for exciting orenergizing thetieldflinagnetl P1 It isprov'ided in any well known-er suitable mannerwithindependent coils'or pairs of connected,'.diametrically opposite, coils ad;-

t-he terminals of whichare connected by bindingscrewse? and metallic rodsc or in any other suitable manner with the segmental plates 0 c ofthe'commutator G.- g The several p'ai'rso'fcommutator sections cc. correspond in number and angularrpositionwith the n um her-andangularposition ofthe armature coils or'pairs ofcoilsa a withreference to the axis ofrotation', and the segmental plates c c of each pair are separated at theirends bysmall 'insulatingspaces only, seas not to. interrupt or break the continuity oflhe current. Z2 1), represent brushes"corresponding in nu mber withthe n umber of the segmental commutain. pairs. These brushes are tach G l-to rods B B carried parallel with the shaft N by; radial arms'B B, which are caps-- ble ofangular movement around-the axis of the commutator each'toward and fromthe 'other.- Between the several pairs ofsegmeu talplates or sections 0 cof the commutator O are interposedcontinuous rings 0" csuitabl y insulated therefrom, and serving to connect the several brushes on one side of the commutator with the brushes on the opposite'sid'e of the commutator and the several coils of the armature .A in series or singlecircuit, one brush of each pair Working with the continu ous ring 0 .on one side-while the'other brush Works withthe continuous ring c on the optor pla'tes or'sectionsc c with which theywork adjustably atposite side of the interposedpair of segmem tal plates 0 c. The terminal brushes on opposite. sides and at opposite ends of the commutator C are connected by conductors with the windings of the field magnet? P. I By the foregoing arrangement and coi1nections of the several armature coils a a;coin mu tater-segments c .0, continuous rings do and brushes 1) b, as clearly indicated in Fig. 1, the several-coils of armature A are includedIfor' a greateror less portionlof each revolution of said armaturein series in the exciting circuit,

and therebyseverallycontribute to the exciting currents Referring to Fig. 10 illustrating on alarge scale, in connection with Figs, 2 11012111 00115 venient mechanism for automatically changing the angular posit-ion of the brush holders and, the distance between; the tworsets-of brushes whereby'the strength ofthe exciting current is variedaccording to variations in the strength of the externaljor working current, Q represents in end elevation the co n' mutator of theexciting circuit; B B, the mov- -able bi'ushcarrying arms provided with seg mental gears D D, which are engaged and actuated by two similar segmental gears 1 D1, suitably 'journaled in fixed bearings and provided with wormgears d d which are on v gaged by oppositesides of adriving worm d".

The shaft of worm df'is provided with a worm gear at which is engaged and drive 1 by the wormjd d d are two. frictionwheels sup ported in constant engagement with each other by suitable fixedbearings, one of v said friction wheels being mounted on the shaft, of the worm (1 d d are two other frictionwheels carried by the upper ends of the arms d d on opposite sides of the shaft Nand each held by a spring actuated bearing in engagement with the friction wheel (1* as shown in Fig. 11. A The arms are pivoted or'fulcrumed concentrically with the friction wheels (1" to suitable supports and are extended and con verge below their sides of a cran'kf, with which they are held in engagement-by a spring cllcounectiug them.

The foregoing mechanism is so constructedfnlcrums to the opposite.

said magnet are connected with the main circult and respectively with the contact points f andf of a circuit making and breaking device comprising avibratory armature f one end of which is interposed between said contact points and-is connected with the working circuit; an electro magnet F placed in a shunt of the working circuit so as to act erases 5 mature F? as shown inlBigs. land 2; x Oneset'ci brushesonly may be made inov-f -able,' it being'essential. simply-to vary the distance between the twov sets t brushes;

and any suitable mechanism and apparatus for accomplishing this end my be employed in'place oi 'thatshown and described.

The operation of automatically regulating the'strengthof theworking current inhuy improvedmachine is as-follows: When the strength of the main working current rises above the desired degree, -the electro magnet overbal ancing the tension of spring f? moves the armature 4 intocontact' with the point f thus diverting a portion of the curr'ent through the coils of-vthe ,niaguet F,

. which, thus energized attracts the adjacent grind of the armature f, turns the crank f and carries one of the friction wheels (1 into 'engagement with the shat'tN or other continu ously rotating driving wheel. Acting thropgh the train of gears previously described said "friction wheel movesthe arms B B with two set'sjof brushes 6 and b toward each'other. The strength of the working circuit isthereby reduced, as-hereinafterexplained, till the spring f balancingtheattraction of the magn'etF brings the armature f to its middle or neutral positionand breaks the circuit connecting themagnet F with the working circuit. The armature f is thus released and returns to its middle position, the friction Wheeld5 is moved out of engagement with the rsh aft N and the fu'rther'approach of the opposite set of'brushes'toward each otheris ar rested. Mfheneverthe working current falls.

below a given degree of strength, the spring f o'verbalancingthe attraction oi the magnet F establishes connection between the main circuit and the coils of the electro magnet F,

which through the adjacent end of the armatureff sets the train in motion in the opposite direction, causing the brush holders and the two sets of brushes to recede from each other. The strength of the working current is thereby increased in the manner hereinafter explained till the attraction of the magnet F balances the tension of the spring f returns the armature f 4 to its middle positio'h and cuts the magnet F? out oi circuit. The armature F as soon as released by the magnet F, is brought to its middle position and the further-movement in that direction of the brush moving train and of the brushes i'sjarrested. The brushes now remain quiescent, occupying the same rela tive positions with reference to each other,

until another variation of the working cur rent moves them in the manner just de: scribed. The effect of changingthe angular position of the movable brushes or the distance between the two sets of brushes is illustrated'in Figs. 12 to 17 inclusive.

It is well understood that an electric current-is induced byv the field magnet in the coils of the armature only when the same areclosedl, When the coils are in open c'ircuit no current is induced therein and conseqdently they are incapable oi energizing jthe field magnet; it is upon this principle that only improved regulation depends.

The strength of the working current of dyname-electric machines is usually regulated by interposing in the circuit more or less resistance thereby wasting energy which isnot needed, whereas'by my method of regulation only therequired electrical energy is produced and mechanical energy and the fuel required to produce the same is econornized tethefnllcst extent. The terminals of each coil. or each pair of coils a at being connected onewi'th one-oi a pair of, segmental commutator platesc c and the other with the other of the same pair, it is obvious that such coil or pairof coils will be in closed circuit only arein contact one with one of said plates and the other with the other plate, and that when both of said brushes rest on thesame plate the coil or coils connected with that pair will be open. While any pair of brushes rests on thesame segmental plate, a and the coil or pair of coils connected with said plate are open, said brushes and plate constitute a conductor between the preceding and succeeding pairs of brushes. The nearer the brushes b andb', approach each other the shorter will be the are or intervalof rotation in which said brushes will rest on opposite when the corresponding pair ct brushes'b b" IOU or different plates 0 c, and the shorter will be the energizing current induced in the coils connected with such plates, and the less will be the eliect of said coils on the field magnet. The brakes between the several pairs of commutator plates 0 c being in lines oblique to the axis of. the commutator the several coils or cuit for only a small part of a rotation, and

contribute very little to the energy of the current andvice versa. I The shaded portions of the field magnet, representing the extent of the arcs ofactivity w hi h the inductive action takes place corresponding to various angular positions of the brushes, illustrate the reciprocal efiects of the field magnet and coils upon each other.

The same principle of arrangement and operation hereinbefore described with reference to the exciting circuit pertains to the worklike the armature A with a number of independent coils or pairs of diametrically oppositecoils a a, the terminals of which are connected-by the binding screws 0 and metallic rods 0 or by other suitable means with the segmental plates 0 c of the commutator ing'circuit'. The armature A is provided C'l These segmental plates correspond in angular position on the commutator with the, angular positionof the coils with which they are connected on the armature, and the breaks or insulating oblique to the axis of thecommutatorf I prefer to separate each pair of segmental plates c by double breaks or insulating spaces between which are short plates 0 c as shown in Eig. '8, so as to out the brushes out v of circuit as the coils'connected therewith construction adjustably attached to shafts B 13 parallel with the axis of the commuta tor and carried by the radialarms 13 -13 one,

or both of which are capable of angular movement about said axis so as to vary the distance between the opposite brushes.

The coils aa, may be composedofa nu mber of sections, capable of being variously are ranged in series, multiple arc, orgroups as indicated in Fig. 1,for the, purposeof producing a current of wider variation as to quality;

Various devices may be employed for coupling the sections of which the coils are composed. I show for the purposein Figs. 2,5,6 and 7 a convenient device by which the several changes in the coupling of the sections may be effected while the niaohine is in op-f It consists ofa disk G fixed upon the eration. shaft N so as to revolve with the and. provided about its lated blocks 9 g, one pair for each coil or pair of coils, springs g-g'-three pairs for each coil' or pair of coils, and plates g g 0ne pair for each coil or pair of coils,- and severally-connected by metallic rods with the blocks g g, as shown in Fig. 2. It consists further of a armature, periphery Withinsudisk H mounted upon the shaft N adjacent to vthe disk G so as to be rotated therewith and at the "same time moved laterally -toward and from said disk G. It is provided about its periphery on one side with insulated.

plates it h corresponding in number and position with the springs g'g on the disk G. The middle. plate h of each group of three plates 7; h is extended across theperiphery of said disk and is coupled at itsopposite end to a short plate h similar to the plates h h as shown in Figs. 6 and 7. The several plates h h are severally connected ingroups of three with the plates of the-corresponding groups on the opposite side of the disk H as shown in Fig. 5. The terminals of thecoils are connected with the bindingscrews g g in' the insulated blocks 9 '9 as shown in Fig. 2 and the terminals of the intermediate sections spaces between the sev .eral pairs of said plates thus occur in lines are severally connected with the insu-- g g -connect the blocks and grouping the armature der to which rings the plates rods or'suitable conductors 7t 7t, as shown in of each coil (these sections being shownon separate armature rings although they may be variously arranged on the same ring or core), are connected inseries with the corresponding groups of springs g g. Suitable conductors attached to the binding screws screws 0 c' in the bars 0 hen the disk I-I isplaced,close to the disk G the bearing points of springs g'g' will pr o. jeot over the periphery of said disk H and all rest upon the plates 9 by means of which the several sections of each coil'are'coupled in multiple arc. When the disk H is moved away from the disk G-the1 plates h h engage the ends of the-springs g g and raise them out of-contact with the. plates 9. Inthis position of the disks the sections of each coil will be coupled in groups of .two and the groups in seriesj By moving the disk H still farther awayfrom said disk- G the severalspringe will rest separately on the individual plates h h and the sections of eachcoil will-be con: nected in series.

' Any suitable mechanism may be employed for moving the disk H into'itsseveral positions while the machine. is in operation. I

have shown for this purposea cam II A connected by a system of lever'sh, h, hiwith'the hub of'said-disk H, as shown in Fig; 2.

g g with the binding 1 c of commutator Cf.

For thepurpo'se of variously connecting ducing currents of different degrees of quantity and intensity, various mechanical devices may be employed. r, In Figs. 2, 4 and 9 of the drawings is shown a convenient devicefor the purpose' It consists of arevoluble cylinder K provided onits' periphery with insulated plates 7c is which are arranged in corre sponding groups parallel with the axis of the cylinder onopposite sides thereof, the plates of each group being severally connected with the corresponding plates of the opposite group by insulated rings 7t wit hin the cylinare attached by 1 tors, as shown in Fig. 2'. Theseveral blocks coils q; a, for pro-Q L L are provided withadjustable contact plates or springs Z Z Or I may make the cylinder-K stationary and move the blocks L Labontit;

arranged tobear upon the plates 70 7a: For the purpose of providing suitable meansmay be employed in connection with this.d'evice'toindicate the various groupings or hinds'of ourrent or both, ob-

tained. i

For convenience in connecting the brushes 1) b of commutator Cwith the several blocks L L of the grouping device, I provide the brush supporting shafts Bi with'insnlated plates 11 set intolon'gitudinal grooves therein and severallyconnected with the several brushes by pins or screws 1) as seen in Fig. 8. By this construction the wires leadingto the blocks L or L of the groupingdevice maybe 44, and the quantity by 1%,.

bunched together and attached to therods b at the ends of the shafts B. Y. Y

' When the two sets of contact springs Z l occupythe positions indicated by dotted lines 1 l, 4- with reference to the plates It on cylinder K and the sections of the coils-a a are connected in series, the sections and coils producing the working current will all be connected inseriesso as to produce a current of the-highest intensity of which the machine is capable. In this particular-case their being twelve coils or pairs of coils consisting of four sections each, fortyeight sections will be connected in series and the inten: sity of the current may be represented by the numeral e8, while the quantity may be rep-' tional pair of coils is united for quantity, the

several double groups in each instance being connected in series with the other groups and the individual coils which are not so grouped. From positions 7, '7 to 12, 12, inclusive, the sections of the coils are grouped in pairs and these groups are connected in series, more or less of said groups being doubled in-the manner just described. Beginning with and following positionslii, l3, a'll'the sections of each coil are joined for quantity, producing in offeet elements of quadruple size, and these are connected in series of individual groups, or of one or more double groups with the remaining individual groups. Between these various groupings of the coils and their com-.

ponent sections, gradual change or variation of the'curreut with respect to its intensity is effected by the movementof the brushes 1)? and 6 as hereinbefore explained; but following positions 19, 19 on the coupling cylinder, 1 do not propose to change the quality of the current by the movementot' the brushes.

In positions 19, 19, all the coils are grouped in pairs, the several. groups, six pairs in number being connected in series. In positions 21, 1 the coils are joined in groups of three,

the several gro'ups','four pairs in all, being connected in series, the intensity of the resulting current being numerically expressed by 4 and its quantity by 12. Finally in the" lastpositions of the contact springs Z l indicated by dotted lines 24, 24:, all the coils together with their-component sections are connected in multiple arc. and the intensity of the resulting current would be expressed numerically by 1, while its quantity would be designated in like manner by'48'. Thus we see that in the machine taken to illustrate my invention, by the various'couplings or groupings of thecoils and their sections of which they are capable, currents-of various qualities maybe produced varying in intensity from 48 to l, and in quantity'from 1 to 48.

I claim 1. In a dynamo electric machine, the'combination with a revolving armature provided with a number of independent coils, of a commutator having a corresponding number of pairs of segmental plates with whichthe terminals of thecorresponding coils are connected, the insulating spaces between the ends of said plates being arranged in linesoblique to the" axis'of rotation, and two sets of brushes arranged in pairs corresponding in number [with said. coils and the pairs of commutator plates with which they are arranged to make contact and connected'with each other and with the exterior circuit in series, one set of brushes being movable circumferentially about the axis of the commutator toward and from the other, whereby said coils are included successively in the exterior circuit and generate an electric current for a greater or less portion of each revolution of, the armature, and when not so included. in the exterior circuit, are open and inoperative, substantially as and for the purposes set forth. e g

2. In a dynamo electric machine, the combination with a revolving armature having a number of independent coils, of a commutator having a like number of pairsof segmental plates with which the terminals of the corresponding'coils are connected, the insulating spaces between the ends of said plates being arranged in lines oblique to the axis of rotation, two sets of brushes arranged to en gage in pairs with the corresponding pairs of commutator plates and connectedwith each other and with the exciting circuit in series, one set being movable circumferentially about the axis of the commutator toward and from the other, whereby said. coils are included successively in the exciting circuit and generate current for a greater or less portion of each revolution of the armature, and when not so included, are open and inactive, a field with the terminal brushes, and electro magnetic mechanismconne'cted with the working circuit and with one set of brushes and arranged to automatically shift said brushes toward and from the other set, according to magnet, the windings ofwhich are connected variations iinthe strength'of the working current, substantially astand for the purposes set forth.

3. In a dynamo-electric machine,-the' combination with a revolving armature provided with a number of independent coils,-of a commutator having a corresponding number of pairs of segmental plates, with which the termi'nals' of the coils are connected, and continuous ringsinterposed betweenthe several bination'with a revolving armature provided with a number of independent'coils each composed of sections, a coupling device arranged to connect the sections offeach coil in series or multiple arcg'a commutator having a corresponding number'of segmental plates with which the terininalsofthe coils are connected,

and two'sets of brushes one set, being inovable toward and .from' the other, whereby said coils areincludedin circuit for a greater or lessportionofieach revolution of the armature, substantially as and forthe purposesset forth. l V

5. In a dynamo-electric machine, the combination with a revolving armature provided with'a number of independent coils, a commutatorlhaving a; corresponding number of paii'siof segmental plates with which the terrnlinalsof the coils are connected, the insulating spaces between the ends of said plates beingin lines oblique to the axis'df rotation, two sets-oftbrushes, one set being movable circumferentiallyaround the commutator toward and from the other, whereby said coils are Included in circuit'for a greater or less portion of each revolution of the armature, and when not so included-are open, and acouplin-g device by which the coils are severally or iii-groups connected witheaoh other and-the exterior circuit inseries and by which they are variously grouped 'for greater or less quantity, substantially'as and for..the purposesset forth.

6; In a dynamo-electric machine, the combination with a revolving armature providedwith a number of'independent coils/anda coupling device consisting of lWOdlSkS revolving concentrically with the'armature, one disk being movable laterally toward-and from the other, and provided with insulated con-- tact pieces variously grouped and connected according to the coupling to be efiected of the sections of the coils andthe other disk being provided with insulated blocks with which the terminals of the coils are connected and insulated springs with which the terminals of the sectionsare connected, arranged to bear against the various contact pieces of the ot-her disk in the dififerent positions of the latter, substantially as and for the purposes set forth.

7. In a dynamo-electric machine, the com ,bination with a revolving armature provided with a number of independent coils, a commutatorhaving a nu mber of pairs segmental plates, with which the terminals of the 00118 are connected,the insulating spaces between the ends of said plates being in lines oblique coils are grouped for quantity and a regulator whereby the strength of the circuit is maintained constant when changes are made for both quantity and intensity, substantially as and for the purposes set forth.

8. In a dynamo-electric machine, the combination with the field magnet,ot a revolving armature provided with a number of independent coils', a commutator provided with a like number of pairs of segmental plates with which theterminals of the coils. are connected,

the insulating spaces between the ends of said plates being in lines oblique to the axis oi rotation, two sets of brushes working in pairs with the corresponding pairs of segmental plates, one set being movable toward and from the other, continuous rings interposed between the several pairs of segmental commutator plates and serving to connect the 'coils through the brushes in series, and mechanism connected with the main circuit and arranged to automatically change the distance between the two sets of brushes according to variations in the strength of said main circuit, substantially.as and for the purposes set forth. I

' 9. In a dynamo-electric machine, the combination with the field magnet and armature supplying the working circuit, of a revolving armature provided with a number of independent coils, means for connecting said coils with each other a commutator having a like number of pairs of segmental plates with which the terminals of said coils are connected, the insulating spaces between the ends of said segmental plates being in lines oblique to the axis of rotation, two sets of brushes working in pairs with the corresponding pairs of segmental plates, one set being movable toward and from the other, the said several coils being connected through said brushes in series, and the terminals connected with the windings of the field magnet, automatic regulating mechanism connected with the movable brush holder, twoelectro magnets and their armature connected with said mech-' anism, a switch arranged to divert a portion of the current through either one of said ma rum nets, and an electro magnet connected with the working circuit so as to operate said switch when the working current exceeds a certainstrength, substantially as and for the purposes set forth.

10. In a dynamo-electric machine, the combination with a revolving armature provided with independent-"coils whichare connected in series withthe windings of the field magnet through two sets of brushes, one set being movable toward and from the other, and

means for connecting said coils with each other of automatic brush adjusting mechanism,.consist-ing of 'two friction wheels-each gearedthrough suitable mechanism withcthe movablebrush holder, a constantly rotated friction driver with which said friction wheels are arranged to engage one ata time, a pivoted armature arranged when moved in one direction to bring one of said friction wheels into engagement withsaid friction driver and when moved in the other direction to bring the other frictionwheel into engagement with said driver, two electro magnets arranged to move said armaturein opposite directions, and an automatic switch consisting of two contact points connected one with the windings'of one or said magnets, the o her with the windings of the other magnet, of an electro-magnet the windings of which are con nected with the working circuit and its armature movable between said contact points, sub stantially as and for the purposes setjforth.

11, In a dynamo-electric machine,'the combination with a revolving armature provided with a number oi independent coils, a commutator having a like number of pairs of seg-' mental plates, with V which the terminals of the corresponding coils are connected and a likenumber of pairs of brushes working with the said segmental commutator platesof a" coupling device, consisting of two sets of-contact springs, individualiy connected with said brushes, and a 'cylinderprovided with contact plates arranged in corresponding and co nected groups on opposite sides thereof,

plates varying in width in different groups so asto couple together two or more pairs of coils,-substantially as and for the purposes set forth,

.12. In a dynamo-electric machine,the com-.

ing groups of insulated contact "plates, and insulated rings connecting the plates on one side or the cylinder with the plates of the corresponding groups on the opposite side, of the cylinder, substantially as and for the purposes set forth.

' 13'. In adyn'amo-electric machine, thecom .bination with a revoluble armature provided with a- .number of independent coils, a commutator havinga like number of pairs or segmental plates with which the terminals oi the correspondingcoils are connected, the 1115i!- lating spaces between the ends of said plates being in lines oblique to' the axis of the com mutator, and two sets of brushes working in pairs with the corresponding pairsot commutator plates, one set of brushes being-"movable toward and from the other, of a coupling device consisting of a revoluble cylinderhavin g two sets of contact platesarranged in cor" responding groups on opposite sides of sa1d cylinder, the plates ot the corresponding opposite groups being electrically conpected, and two sets of contact springs on opposite sides of said cylinder, severally connected with said brushes, substantially as and for the purposes set forth. t

'14. In a dynamo-electric machine, the combination with a revolving armature having a number of :independentcoils, of a commutator havinga like number of pairs of segmental plateswith which the terminals of the corresponding coils are connected, two sets of brushes arranged-- to work in pairswith' the'correspondingpairs of commutator plates,

brush supporting rods or bars parallel with the axis of the com mutator provided with insulated conductors which are inserted in longitudinal grooves insaid rods or bars and are severally connected with said brushes, and a coupling device consisting of .two sets of contacts, severally connected with said ,insulated conductors at the ends of 'the' rods or bars inwhich they are inserted, and a revoluole cylinder providedwith insulated plates "correspondingly, grouped :on' opposite sides .thereof,-substantially as and fort-he purposes set forth.

15. "Inady'namo-electricmachine, the corn"- bination with a cornmutatoig'dividedtransversely to its axis into anumber of sections, two sets of brushes working in pairs with corresponding sections ofthe commutator, brush 'supportingrods or barsarranged par- .allel with the periphery of the commutator and formed with longitudinal grooves, and insulated conductors inserted in said grooves and each connected with abrush, substanti ally as and for the purposes set forth.

.' In testimony that I claim the foregoing as IIO my own I aflix my signature in presence of two witnesses. n

' CHARLES L. F. MULLER. Witnesses:

OHAs. L. Goss, E. H. BOTTUM. 

